Elastic fabric



D. M. CLARK ELASTIC FABRIC Get. 1, 1935.

Filed Jan. 14, 1935 w 6 E :2 a j y p z AH IMWZ e ,J 7

Patented Oct. 1, 1935 UNITED STATES PATENT OFFICE aomm ELASTIC FABRIC Imm M. cm, mm, Mass.

Application January 14, 1935, Serial No. 1,639 *1 Claims. (01. 06-402).

threads between predetermined courses of the l knitted fabric, andstretch at right angles thereto is provided by knitting into said fabricone or more courses of elastic material. The elastic threads which areknitted in must be relatively fine in order to provide a garmentrelatively light 15 in weight and having a relatively smooth surface.

Such fabrics thus necessarily incorporate, in general, both a relativelyfine elastic thread as small as or smaller than one-seventieth of aninch square in cross section which forms certain of the 20 knittedcourses, and a relatively heavy elastic thread as large as or largerthan one-sixtieth of an inch square in cross section which is laid inthe fabric without being knitted therein. One of the principal objectsof the present invention is to 25 provide a knitted fabric in whichstretch in two directions at right angles to each other is provided by asingle relatively heavy type of elastic thread so arranged in the fabricas to provide for a substantial stretch in both directions.

30 Elastic fabrics of this type are frequently used in supporting andconfining garments, and the rubber incorporated in the elastic threadsdeteriorates as a result of the action of perspiration and atmosphericelements on the surface thereof.

35 The larger the cross sectional area of the rubber in the thread, thelonger it will last without substantial deterioration, and a furtherobject of the invention is accordingly to provide for the use ofrelatively large elastic threads in obtaining the 40 stretch in bothdirections without the necessity for using any relatively fine elasticthreads, and without making the fabric too thick or rough on thesurfaces thereof.

Where the elastic threads are laid into the usual fabric as it isknitted, there is nothing to hold said threads against sliding movementwithin the fabric as the result of a pull on said fabric lengthwise ofthe threads. Such fabrics cannot be cut 50 and successfully usedthereafter without slipping of the elastic threads since-there is no wayfor positively securing the ends of the elastic threads, and breakage ofan elastic thread, which allows sliding of said thread, materiallyreduces the 55 elastic characteristics of the fabric and also causesunsightly imperfections. A further object of the present invention is toprovide for the securing of the several elastic threads within thefabric so that they will be held in proper position if they shouldbreak, and so that such fabrics may be cut in forming articlestherefrom.

Other and further objects and advantages of the invention will morefully appear from the following detailed description taken in connectionwith the accompanying drawing, in which- 10 Fig. 1 is a diagrammaticview of a portion of the .fabric embodying the invention, said fabricbeing stretched substantially to the limit in both directions and beinggreatly enlarged.

Fig. 2 is an elevation of a garment incorporating the fabric of theinvention. Like reference characters refer to like parts in thedifferent figures.

The invention resides in so knitting the elastic threads into the fabricthat stretch in both directions may be obtained with only a singleelastic thread of relatively large size in proportion to the inelasticthreads. Referring to Fig. 1, the, fabric, which can be knit on thewell-known flat knitting machine, or on the circular dial and cylindermachine, or on certain other familiar types of knitting machines, isdescribed as if it were knitted on a circular machine. Such a machinehas a plurality of cylinder needles I and a plurality. of dial needles 2arranged in staggered relation to the cylinder needles and extending atan angle thereto as in the usual circular machine. These machines form atubular fabric, and each of the needles is individually controlled todetermine the number of stitches and the type of knitting, as is wellknown.

. 'In the knitting of the fabric on a circular machine, threads 3, l, 5and 6 respectively, are knitted successively during each completerotation of the movable part of the machine. 40 Threads 1 and 8, whichare the heavy elastic threads, are normally laid into the rows ofknitting between successive courses without being directly knitted intothe fabric, the thread being positioned between the loops formed by thecylinder needles and the loops formed by the dial needles. These elasticthreads normally comprise filaments of rubber which have been wound withnon-elastic threads of any suitable character, such as cotton, silk, orrayon. This windin Considering each thread separately, the thread 3 isknit by each of the dial needles, but each alternate cylinder needleperforms no knitting operation on said thread so that the latter passesby each fourth loop in the preceding thread or course without beingknitted into the fabric. Each alternate cylinder needle which does notform a loop in the thread 3 is, however, arranged and actuated so as toform a loop in the elastic thread I which engages with the loop in thepreceding course, the elastic thread being engaged by the cylinderneedle before the loops are formed in the thread 3. The thread 4 whichforms the course following the thread 3 is knitted by each of the dialneedles and also by each of the cylinder needles in the usual manner,the loops in said thread 4 engaging with the loops formed by the needlesin the thread 3, with the exception, however, that where the cylinderneedles fail to form loops in the thread 3 and instead form loops inthe-elastic thread 1, the corresponding needle passes the loop 'ofthethread 4 through the loop formed in the elastic thread. By the provisionof the loops in the elastic thread it is possible to obtain a stretchfor the fabric in two directionsat right angles to each other. It willbe noted that the elastic thread I is normally positioned between theloops formed by the cylinder needles and the loop formed by thedialneedles so that it is positioned between the twoouter-surfaces of thefabric.

The thread 5, which is inelastic, is knitted in the same manner as thethread 3 above described, with the exception, however, that the cylinderneedles which form loops in the thread 3 do not form loops in the thread5, thereby staggering the position of the loops in the elastic threads Iand 8, as apparent from Fig. 2. The thread 8, as is clearly shown, islocated between the cylinder and dial loops formed in the thread 4,except where it is engaged by the loops in the thread 6, which latter isknitted in the same manner as the thread 4 above described. It will beapparent that the loops in the elastic threads 1 and 8 need not ofnecessity be staggered, although the latter arrangement provides aslightly greater stretch parallel to the wales of knitting than when theloops are not staggered.

Since the thread 3 is not looped through each of the loops in the thread6, it will be apparent that the threads 3 and I together form a completecourse in the fabric. That is to say, where the thread 3 is not loopedthrough the loops in the thread 6, the elastic thread I is loopedtherethrough and the fabric is accordingly continuous, with the threads3 and I together forming a single course.

The thread 3 forms the course subsequent to the thread 6 and this threadis knitted in precisely the same manner as the thread 3 having loopsformed therein by the same cylinder and dial needles, with each secondcylinder needle omitting a stitch, said needle engaging instead with theelastic thread I which is located within the fabric in the same manneras the thread I, the cylinder needle engaging with the elastic thread Ibefore engaging with the thread 3', as will be apparent. Where theneedle engages with the elastic thread instead of with the inelastic,

thread a single yarn stitch is formed; the term single yarn indicatingthat both elastic and inelastic stitches are not formed together butthat either the elastic or the inelastic thread is looped withoutincorporating a loop in the other thread on the same needle.

The arrangement shown in Fig. 1 represents the fabric as stretchedsubstantially at a maximum in both directions, so that very definiteloops are defined in the elastic threads I and 3. When the fabric is notstretched, however, after. 5 it has been knitted, the elastic threads,being much stiffer than the other threads, tend to become straightwithin the fabric, thereby drawing upwardly on the loops in the threads4 and i to contract the fabric very substantially in 8. dll0 rection atright angles to the general direction of the elastic threads. By thisstraightening of the elastic threads, portions of the loops of thethreads 6 are drawn into the base of the loops in the thread 4, so thata very emphatic contrac- 15 tion of the fabric takes place.

The fabric of this type is intended to be incorporated in any structure,such as body restraining members of which girdles are an example. Asshown in Fig. 2, the girdle 3 is formed 20 of this material and hassufficient elasticity to conform to the portion of the anatomy encasedtherein. By varying'the tension on the elastic thread as it ispositioned within the fabric during the knitting thereof, it is possibleto con- 25 trol the diameter or width of the finished garment atdifferent portions thereof without changing the number of needles in theknitting machine operating upon the fabric.

Since the threads 4 and 6 are wrapped around 30 the elastic threads Iand 8 when the fabric is in an unstretched condition, these threadsprevent sliding of the elastic thread through the fabric so that if anelastic thread should break,

its eifectiveness is not lost since the inelastic 35- threads will holdsaid elastic threads in proper position. Since the elastic threads canbe held against longitudinal sliding movement within the fabric, it willbe apparent that the fabric may be' provided with pockets or bulges that40 can be confined to localized areas in the garment. These pockets orbulges are formed by placing the elastic within the fabric inpredetermined areas at a low tension as compared to the tension appliedto the rubber in the remainder of the garment. These pockets or bulgesremain properly located within the fabric and can be positioned in anydesired part thereof, as will be apparent.

Stretch in a direction at right angles to the normal direction of theelastic thread may be eliminated in certain portions of the garmentwhere it is desired, by so controlling the cylinder needles I that inaddition to forming loops in the elastic threads at intervals, saidneedles also form loops in the corresponding inelastic threads. That isto say, each alternate cylinder needle engages with the elastic thread Iand forms a loop therein which extends through the previously formedloop in the thread 6'. The thread 3 is then knitted by the cylinderneedle I instead of being omitted as in the showing of Fig. 1, the loopof the thread 3 passing through the loop in the elastic thread I.Subsequently, the same needle I loops the thread 4 through the loopsformed in the thread 3. Thus in the rows or wales of knitting formed bythe cylinder needles I, there is an additional stitch inserted,

instead of omitting the stitch asindicated in cular knitting machine, itwill be apparent that the same structure may be incorporated in a fabricwhen the latter is knitted on other types of machines, and the inventionis not intended to be limited to a fabric knit on any specific type ofmachine.

, From the foregoing, it will be apparent that the invention providesfor the production of an elastic fabric which is capable of stretchinginboth directions, but which incorporates only one relatively large typeof elastic thread which is so positioned in the fabric as to provide notonly for stretch in the direction in which said thread extends, but alsoin the direction at right angles thereto, this latter stretch beingprovided by knitting said elastic threadinto the fabric at spaced pointstherein. The stretch can be concentrated or minimized in localized partsof the fabric, since the threads are held against sliding movement inthe fabric, and stretch in one direction may be eliminated in localizedparts by the formation of the loops in the inelastic thread wherestretch in; only one direction is desired. v

I claim: a

1. A knitted elastic fabric having stretchin two directions in whichcertain courses consist of inelastic thread and the remaining coursesconsist of elastic and inelastic thread, said elastic thread beingknitted into certain wales of the fabric, and the inelastic thread beingknitted only into the remaining wales in the same course.

2. A knitted elastic fabric having stretch in two directions in whichcertain courses consist of inelastic thread and the remaining coursesconsist of elastic and inelastic thread, said elastic thread beingknitted into certain wales only of the fabric, and the inelastic threadbeing knitted into the remaining wales in the same course, stitchesbeing omitted in said inelastic thread in certain of the wales ,wherethe elastic thread is knitted.

t -5 3. A knitted elastic fabric having stretch in 'consist of elasticand inelastic stitches, said elastic stitches being formed in certainwales only of the fabric and the inelastic stitches in the same coursebeing omitted at least in certain of the wales where the elasticstitches are formed.

5. In the method of forming an elastic fabric the steps which compriseforming all 'of the stitches in certain of the courses of inelasticthread and forming the stitches of the remaining courses of elastic andinelastic thread, the

, stitches of the inelastic thread in said remain- I same course incertain of said spaced wales.

' 7,. A knitted elastic fabric having stretch in two directions, saidfabric consisting mainly of inelastic stitches, elastic stitches beingformed only in certain spaced wales in certain courses, 40 inelasticstitches being omitted where the elastic stitches are formed, theelastic stitches being formed of elasticthreads otherwise laid in thefabric.-

DAVID M. CLARK,

